Some outdoor lighting fixtures, such as some roadway lighting fixtures, often need to include a heat sink to dissipate heat from light sources and other electrical components of the light fixtures. In order to have a heat sink with adequate surface area to dissipate heat from light sources of an outdoor lighting fixture, heat sinks used in outdoor lighting fixtures are generally made by extrusion or die casting. For example, outdoor light fixture heat sinks often have protruding structures such as fins that are designed to increase the surface area of the heat sinks. However, as light sources, such as light emitting diodes, become more efficient, required heat sink surface area has generally decreased.
Outdoor light fixtures are also typically exposed to various weather conditions such as rain that can damage electronic components including the light sources. Further, reduction of sky-glow and glare caused by outdoor lighting fixtures is desirable. For example, sky-glow is typically caused by artificial light sources (such as outdoor lighting fixtures) and can produce a luminous haze that can, for example, limit visibility of the stars.
Thus, a structure of an outdoor lighting fixture that cost effectively provides an adequate heat sink and further functions to reduce water damage to the lighting fixture while resulting in reduced sky glow and glare is desirable.